The present disclosure relates to disk data detection, and more particularly, to data detectors for optical disk drives. An alternative to the conventional Viterbi detector (VD) is provided.
The Viterbi detector is widely used in the industry for optical disk drive data detection. This is partly because the VD was a proven technology in magnetic hard disk drives over two decades of use. A significant drawback of the Viterbi detector is its speed bottleneck. In the Viterbi detector, three particular operations are to be completed during a single clock cycle. The three operations are Add, Compare and Select (ACS) operations. To combat this speed bottleneck, a radix-x (x=2, 4, etc.) approach may be utilized for a parallel structure to decrease clock frequency, which exacerbates the drawback of increased hardware die size and complexity. In addition, since a Viterbi detector is a linear detector, it lacks the power to correct nonlinear impairments. Thus, the drawbacks and disadvantages of the prior art Viterbi detector include its speed, die size and power.